Phonograph



sept. 7 1926.

. 1,598,607 Z. ECKELBARGER PHoNoGRArH Filed March 17, 1924 Patented Sept. 7, 1926.

PATENT OFFICE.

ZENA ECKELBARGER, OF GOSHEN, INDIANA.

IPI-IONOG-RAPIEI.

Application filed March 17, 1924. Serial No. 699,700.

rlhis invention relates to phonographs and particularly to the sound box therefor.

The principal object of the invention is to provide means for adjusting the vibrator arm of the sound box of a phonograph, whereby the tone volume may be regulated, and whereby a softer tone, one free from metallicA sounds, is produced.

The preferred embodiment oi the invention is illustrated in the accompanying drawing in which Figure 1 is a side elevation of a sound box of a phonograph having my invention applied thereto; Fig. 2 illustrates two views, a side elevation and plan, of the hub oi the vibrator arm; and Fig. 3 is an enlarged fragmental view ot' a portion of the sound box in section and the vibrator arm adjustment means.

Similar numerals of reference indicate like parts throughout theseveral views on the drawing.

Referring to the details of the drawing the numeral l indicates a phonograph sound box provided with a depending fork 2 at its 25 periphery, said fork being adapted to carry the vibrator arm 3, as hereinafter described. The inner end of the vibrator arm 3 extends to the center of the sound box 1 and engages the diaphragm-not shown-as is well known inthe art. The outer end of the arm 3 is provided with the two hub sections 4 and 5 projecting in opposite directions and disposed between the two prongs of the fork 2. The arm hubs 4 and 5 are pivotally mounted upon the two pins S-only one being shown-which may be screw-threaded through the prongs of the fork 2 axially of each other and engage in the recesses 6 and 7 formed coaxially in the ends of the hubs 4 40 and 5.

rlhe numeral 9 indicates the hub of the two stylus arms 10 and 11 which are provided with the varied stylus needles or points 12 and 13, respectively, which are described and claimed in my copending application Serial Number 409,292, sound reproducing device, and which forms no part of this invention. The hub 9 is rotatably mounted upon the shaft 14 which is suitably mounted in the socket 15 formed in the boss 16 oi' the hub of the arm 3 and coaxially therewith, Fig. 3.

The numeral 17 indicates an arm rigid with the hub of the arm 3 and projecting laterally therefrom through the opening 18 formed .ing 19 which is rigid with the box 1 and positioned above the 'fork 2. The casing 19 is tubular, as stated, the outer end whereof is adapted to be closed by the screw plug 20 adjustably mounted therein. The chamber or interior of the casing 19 is intersected intermediate its extremities byk the lateral opening 1S to admit the arm 17 thereinto, and the balls 21 and 22, disposed within said casing upon opposite sides of the arm 17 are caused to yieldingly engage said arm by the coil tension springs 23 and 24, respectively, also arranged within said casing. The spring 24 may be seated at the end wall of the casing interior, and spring 23 is seated upon t-he adjustable plug 207 whereby tension of said springs may be regulated and adjustment of the arm 17 and vibrator arm 3 effected to regulate the tone volume and quality and to eliminate the vibration of the parts of the device.

I claim:

In a device of the class described, the combination with a sound box provided with a pivotally mounted vibrator arm, of a hollow casing carried by said sound box and provided with a lateral opening, an adjustment arm projecting laterally from said vibrator arm and extending through said casmg opening to the casing interior, a spring pressed ball engaging on each side of vsaid arm and disposed within said casing, and means to adjust the tension of the springs engaging said balls.

In witness whereof I have hereunto affixed my hand this 10th day of March, 1924.

ZENA ECKELBARGER.

in the under side of the hollow cas- 

